For some time, as shown in Patent Document 1 (Japanese Published Unexamined Patent Application 2013-15523), urinals have been known in which, in order to constrain the occurrence of uric scale, an equipment protection flush operation was performed when the number of uses or a usage time interval had respectively reached predetermined measurement values. In this urinal equipment protection flush operation, flush water is spouted not only from the toilet spout portion but also from a hand sink spout portion to raise the instantaneous flow volume during the equipment protection flush operation to be greater than the instantaneous flow volume when the urinal main unit is flushed, thereby raising the water level inside the horizontal plumbing to flush the water line, which is the border portion between urine-mixed flush water and air.
Also, as shown in Patent Document 2 (Japanese Published Unexamined Patent Application 2014-062459), there is a known problem in that due to reverse flow of flush water mixed with urine to the upstream side of horizontal plumbing installed downstream of the urinal for discharge, urine remains upstream after completion of discharge and uric scale forms; to solve this problem a urinal is known in which a first flushing mode for substituting flush water for urine which remains, pooled in a trap, and a second flushing mode for flushing residual urine left in the horizontal plumbing by the first flushing mode, are executed.